They will never do such a thing, it's easy, some people with low lever characters will slowly migrate to bartz, or even more, people will leave the game, it's too rushy to take any actions since Bartz only opened yesterday, let some time pass
Or maybe opening a new server with "transfer only" policy instead of "no transfers and only new accounts" would help to balance the overloaded traffic a bit. I would gladly move to a new server and when the server transfer service was introduced, entire clans did that. Obviously sometimes for the sole reason to start easily ruling a quiet RP server when they had no such luck in their original location but still... With the restriction of keeping some months before you can change server again, it might start new communities formed of existing players and actually allow mid-level chars do get some action without having to compete with hundreds of others for a quest mob (to get a quest done that is supposed to make it easier for you to advance in game).
It's very welcome to have a living community again but if it's killing the fun due to technical issues, it's time someone does something about it. Me for example switched to playing other games for a while and only lurking in the less crowded servers at odd hours to get some idea of the new content :p